In Vietnam, flooding adaptation in rural areas is inseparable from the informal actions taken by households at the micro-scale. However, the country’s ongoing urban transition puts major socio-economic and environmental pressure on these households and the rural communities to which they belong. Through the case study of a periurban village community of Hanoi, this thesis aims to understand how these pressures affect pre-existing populations’ vulnerability to flooding and their adaptive capacity. The analysis focuses on the micro-scale, an approach mostly used in rural studies in Vietnam. Applied to the periurban context of Hanoi, through questionnaire surveys and semi-structured interviews, this approach provides a more detailed and nuanced understanding of urbanization’s consequences on flooding vulnerability and adaptation. It reveals how households perceive their own vulnerability and the capacities that they have to reduce it in the current urban transition context. The analysis shows the periurbanization of Hanoi has differentiated impacts on livelihoods across the urbanizing village’s community. This influences the adaptive capacity of each household and the adaptation pathways they take. Some households benefit from new economic opportunities associated with urbanization to reduce their vulnerability and counterbalance the adverse effects of this phenomenon on flood exposure. Others are however forced to live in a deeper state of vulnerability exacerbated by their lack of financial resources and their livehoods’ precarity. Finally, the results suggest that adaptation opportunities observed in the present do not automatically constitute an adequate preparation in view of a future that will likely be marked by more acute climate change and urbanization pressures.